Fluid control structure



1967 J, B. HOUSTON ETAL 3,35 ,916

FLUID CONTROL STRUCTURE 2 Sheets-Sheet 2 Filed Oct. 24, 1965 71 Jan 7x04United States Patent 3,359,916 FLUID CONTROL STRUCTURE Joe B. Houston,2267 Roscomare Road, Los Angeles, Calif. 90024, and Harvey H. Davis,4145 Lynd Ave., Arcadia, Calif. 91006 Filed Oct. 24, 1965, Ser. No.504,468 Claims. (Cl. 103-152) ABSTRACT OF THE DISCLOSURE Acollapsible-duct pump incorporating structure to collapse an intakesection of the duct initially so that the remainder of the duct can becollapsed by air pressure to force pumpage from the outlet withoutbackflow. Incompressible fluid about the duct reduces the requiredairflow and various arrangements are disclosed for cycling the pump.Pluralities of the pumps are shown both in series and parallelarrangements.

The present invention relates to a fluid control system for controllingthe movement of a fluid, a slurry of relatively high viscosity, or evena somewhat solid materia It has become rather widespread practice in thebuilding industry to place concrete by forcing it through a duct to adesired location while it is in a slurry or somewhat fluid state. Thistechnique is particularly useful in transporting concrete to the upperfloors of a multi-story building. However, difliculties in using thetechnique sometimes stem from the pump or other actuator employed tomove the slurry. For example, prior pumps for use in this applicationconventionally employ drive mechanisms which develop considerableinertia. As a result, if for some reason the flow duct becomesobstructed or blocked before the drive mechanism can be stopped, it mayapply intolerable pressure to the slurry. Upon such an occurrence, theduct may break propelling concrete slurry and aggregate with dangerousforce.

Another aspect of prior pumps or actuator mechanisms for moving concreteslurries is their requirement for considerable capacity for developinghigh pressures. As a result, these structures have generally been quiteexpensive to manufacture, use and maintain. Furthermore, the high fluidpressures and mechanical forces of prior pumps have often preventedtheir use for placing lightweight concrete in which the aggregate wouldbreak down or become water impregnated under such forces. These forcessometimes also tend to impair the final quality of regular orrock-aggregate concrete.

One other aspect of prior pumps for use in moving concrete has been theabrading effect of aggregate materials on components of the pump thatactually engage the concrete. That is, prior pumps have normally beensubject to considerable wear resulting from direct mechanical forceapplied to abrasive aggregates.

In view of these considerations, a need exists for an improved pump orfluid control structure which may be employed to move, and to controlthe movement of high viscosity liquids as concrete, various slurries andother fluids or semi-fluids. Another specific exemplary application fora pump valve or fluid control structure which has relatively few movingparts and essentially no solid moving parts which contact the controlledfluid is for controlling the flow of corrosive fluids.

It is therefore a general object of the present invention to provide animproved fluid control structure as may be embodied for example in avalve or a pump, for overcoming the objections of various structures ofthe prior art as considered above.

Another object of the present invention is to provide an improvedinvention pump, wherein relatively few moving parts are provided, andwhich is useful for pumping generally diflicult substances as concreteand corrosive fluids.

Still another object of the present invention is to provide an improvedconcrete pump which can be relatively inexpensively manufactured andmaintained, which is economical in use, and reliable in operation.

Still one other object of the present invention is to provide animproved concrete pump, the operation of which avoids impacting abrasiveaggregates against wear surfaces under direct mechanical force.

A further object of the present invention is to provide an improvedbasic fluid control structure as may be variously embodied to move andcontrol the movement of fluids, semi-fluids and even semi-solids; thetransportation of which have in the past presented a considerableproblem.

In accordance with these objects, the objective structure hereofincludes a flexible or deformable duct which is adapted to be connectedto a source of pumpage and which is contained within a closed housingwhich incorporates means for varying the fluid pressure within the spacebetween the duct and the housing whereby to control the I movement of oractually move the pumpage.

These and other objects hereof will be apparent to one skilled in theart from a consideration of the following, in conjunction with theappended drawings, wherein:

FIGURE 1 is a perspective view of a concrete delivery structureincorporating the principles of the present invention;

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1;

FIGURE 3 is a central horizontal section taken through FIGURE 2;

FIGURE 4 is a sectional diagrammatic view of a structure in accordancewith the present invention;

FIGURE 5 is a fragmentary view similar to FIGURE 4, showing thecomponents in another operating relationship;

FIGURE 6 is a view similar to FIGURE 5 showing the components in stillanother operating relationship;

FIGURE 7 is a sectional diagrammatic view of another structure inaccordance with the present invention;

FIGURE 8 is a sectional diagrammatic view of still another structure inaccordance with the present invention; and

FIGURE 9 is a sectional diagrammatic view of still another structure inaccordance with the present invention.

Refer-ring initially to FIGURE 1, there is shown a delivery structure 10for placing concrete in a building 12. More specifically, a tower 14supports a hopper 16 at various heights and provides a bucket elevatorfor delivering concrete to the hopper. Concrete placed in the hopper 16passes through an outlet 18 which is directly connected to a pump 20that functions to deliver the concrete at a desired location within thebuilding 12 through a hose 22. The pump 20 is pneumatically poweredthrough an air line which is adapted to be connected to a source of airunder pressure. In operaiton, air passing from the line 24 into the pump20 is controlled by a cycling system- 26 as will now be considered ingreater detail to further explain the structure of the system withreference to FIGURES 4, 5 and 6.

Referring initially to FIGURE 4, a bucket 30 of an elevator as shown inFIGURE 1, is illustrated in a dumping posiiton and also shown in phantomin a position immediately before the dumping position. Concrete 31 isdelivered by the bucket 30 into a hopper 32, the lower end 34 of whichis reduced in section and connected through a connector 35 to a rigidingress duct or tube 36.

The lower end 34 of the hopper 32 contains a fixed blowby safety deviceor shield 38 in the form of a circular, concave-convex rigid structurefor bleeding ofi air in the event of a component failure.

The pump intake tube 36 is sealed telescopically into a closed shell orhousing 40 which may be of somewhat elongate cylindrical form and madeof metal or other rigid material, capable of confining substantialpressure. An outlet tube 42 incorporating a reducing cone is sealed inthe opposed end of the housing 40, also extending therein. The internalextensions 44 and 46 of the tubes 36 and 42 respectively then receive acylindrical diaphragm, or flexible duct 48 which is rigidly fixed toextend the full length of the housing 40.

The duct 48 may comprise a rubber hose, reinforced with synthetic fabricas nylon for example, to provide adequate flexibility for collapse, andgood wear characteristics with relatively little fatigue deterioration.The concentric placement of the duct 48 within the housing 40 provides achamber 49 between these members which contains oil 50 or otherincompressible fluid.

In the operation of the structure as shown in FIGURE 4, concrete 31flows into the duct 48 from the hopper 32 and is then exhausted from theduct by its collapse under pressure to force the concrete through theexhaust tube 42 and a hose 52. To cycle the pressurization of thechamber 49, a probe head 54 senses the operating phase of the duct 48.When the duct 48 is collapsed, the chamber 49 is opened to relieve thepressure therein and allow concrete 31 to gravity flow into the duct 48.Then when the duct 48 is filled with concrete, the chamber 49 ispressurized, collapsing the duct 48 to move the concrete.

Considering the control structure in greater detail, the probe head 54is carried on an elongate rod shaft 60 which passes in sealedrelationship through the housing 40 to engage a movable contact 62 of aswitch 64. The contact 62 is electrically coupled to a source ofpotential and mechanically connected to a compression spring 66 which isfixed so as to urge the probe head 54 into the housing 40, actingthrough the movable contact 62.

The movable contact 62 operates in cooperation with a fixed contact 68that is connected to a time-delay circuit 70, which may comprise a timedelay relay, the operation of which lags that of the control switch 64,as well-known in the prior art. That is the time-delay circuit 70applies electrical control signals from the switch 64 to a solenoidvalve control 72 in time delayed relationship to the signals from theswitch 64.

The solenoid valve control 72 actuates a two-way valve 74 which is shownin its residual or quiescent position,

connecting an air channel 78 of the housing 40, to an exhaust outlet 80.Upon energization of the solenoid valve control 72, the valve 74 isrevolved in a clockwise direction to connect the air channel 78 to anintake 82, adapted to be connected to a source of air under pressure.

Considering the operation of the system in greater detail, referencewill now be made to FIGURES and 6, along with FIGURE 4. The similarcomponents and elements in all these figures are identical by likereference numerals. Referring first to FIGURE 4, in thestage-ofoperation illustrated the duct 48 has filled with concrete 31flowing under gravity force from the hopper 32. The probe head 54 isurged outward by the expanded or open shape of the duct 48 so that theswitch 64 is closed applying a control signal to the time-delay circuit70; however, that circuit is depicted in a state of delaying theapplication of the control signal to actuate the solenoid valve control72.

At the expiration of the delay period illustrated in FIGURE 4 asexplained above, the solenoid valve control actuates the valve 74 byimparting a quarter-revolution clockwise movement to the valve as shownin FIGURE 5. It is to be noted that the control structure as illustrateddashed line in FIGURES 5 and 6.

With the valve 74 actuated as shown in FIGURE 5, air under pressureenters the housing 40 through the channel 78 to pressurize the chamber49. The pressure in the chamber 49 is applied somewhat uniformly to theflexible duct 48; however, in view of the static head of the concretecontained in the duct 48, that member collapse initially at a pinch 80,near the top of the duct. That is, as the static head along the lengthof the duct 48 is lowest near the top, collapse initially occurs nearthe top.

The pinch 80 as shown in FIGURE 5 becomes a valve to prevent back flowinto the tube 36, and also forms the leading edge of the pump in action.That is, as the chamber 49 is pressurized, the duct 48 continues tocollapse along its length extending the pinch 80 (FIGURE 5) to acollapse 82 (FIGURE 6) and thereby expelling concrete through the tube42.

At the conclusion of the exhaust action, as depicted in FIGURE 6, theprobe head 54 moved inward with the collapse of the duct 48, therebyallowing the contact 62 to withdraw from the contact 68. As a result,after a brief time delay incurred by the circuit 70, the solenoid valvecontrol is de-energized, allowing the valve 74 to return the position asshown in FIGURE 4 connecting the chamber 49, to the exhaust channel 80.Therefore, the chamber 49 is relieved allowing concrete 31 to re-filledthe duct 48 so the cycle can be repeated. In this manner, the systemcycles and recycles, pumping concrete from the hopper 32 out through thetube 42 for placement through pipes, hoses, conduits or other passagesat the desired placement location.

It is to be noted, that in the operation of the system as shown, thevolume of pressurized air or other gas which is spent in a cycle ofoperation is limited somewhat as the actual volume of concrete that isactually displaced. That is as the oil 50 substantially fills the voidof the chamber 4? when the duct 48 is loaded, the space developed in thechamber 49 is substantially limited by the volume of concrete that isdisplaced. Of course, this arrangement obtains a considerableimprovement in operating efliciency.

It is readily apparent that the basic structure hereof may take a widevariety of different forms one rather specific design of which has beenfound effective and is shown in detail in FIGURES 2 and 3. In thisdesign, the outlet 18 (FIGURE 1) from the hopper 16 is connected to arigid intake duct (FIGURE 2) entering the pump structure. An externalflange 102 is welded onto the duct 100 and is aflixed by bolts to aclamp ring 104, with the end 106 of a flexible pump sleeve 108therebe-tween. The sleeve 108 is similar to the flexible duct aspreviously described and may comprise an elongate cylinder of neoprenerubber reinforced with steel mesh and nylon. In the design, the sleeveis approximately ten inches in diameter and some eight feel in length;however, it is stressed that these dimensions are, of Course, merelyillustrative.

The duct 100 bearing the sleeve 108 extends into a chamber defined by apair of elongate mating channels -112 (FIGURE 3) which are somewhatconcave-convex in section. These channels are mated together to definean elongate cylindrical chamber 114 with parallel opposed elongatetapered slots 116 and 118 extending along the length thereof.structurally the two channels may be formed of steel and are held inmated relationship by four exterior braces 120 (FIGURE 2). The braces120 comprising steel for example are Welded to the channels 112 whichare in turn welded to the ring 104 (FIGURE 2) at the upper end thereof.The lower ends of the channels 112 are welded to a ring 122 which is inturn alfixed by bolts 124 to a flange 126 which is welded to an exitduct or tube 130. The tube 130 receives the lower end of the sleeve 108,molded thereon over annular ridges 132, and is connected to a hose ortubing 22 (FIGURE 1) through which concrete is delivered.

In the operation of the structure as shown in FIG;

URES 2 and 3 air is received under pressure through an intake 134(FIGURE 2) and the state of the operating cycle is sensed by a probestructure 138 for control purposes as previously described. In view ofthis structural description of the design embodiment of FIGURES 1, 2,and 3, the detailed operation thereof will now be to exhaust theconcrete therein out of the tube 130. Asthe sleeve 108 collapses, itassumes a configuration as,

shown by the phantom sleeve 108a (FIGURE 2). It is to be noted, that thecollapsed sleeve 108, at the upper end thereof engages rings 142 and aball 144 held spaced apart by brackets 146 that are afiixed t the duct100 asby welding to define a somewhat conical shape for internalsupport. The arrangement of this structure is also shown in the uppersection of FIGURE 3 taken through.

the duct 100 above the flange 102. The lower section of FIGURE 2 istaken from a central location in the pump.

The existing concrete from the sleeve 108 is moved toward the desireddelivery location and when the evacuation is complete another cycle isinitiated by concrete flowing to refill the sleeve 108. It is to benoted that in the operation of the system, the pressures applied to theconcrete never exceed the regulated pressure of the ap-' plied air.Furthermore, the concrete is not subjected to mechanical shock forces asby pistons or the like. Still further, the flexible sleeve, gland orpump duct in the system is not mechanically driven, with the result thatextended period of trouble-free operation can be expected.

In some instances, it may be desirable to operate a.

form of the structure hereof with the collapsible sleeve or ductpositioned horizontally, to move pumpage having some initial head. Insuch an instance, additional structure may be provided to form theinitial pinch at the desired location. That is, as there 'is nosubstantial static head differential along the length of the horizontalsleeve, structure is provided to form the pinch at the desired locationas shown in FIGURE 8.

The structure shown is generally similar to that of FIG- URE 4 and likeelements bear the same reference numerals. The additional elementscomprise a pair of opposed pneumatic rams 150 and 152 that are connectedto the pump air intake 78. The ram 150 includes a pneumatic actuator 154for driving a pinch plunger 156. Similarly, the ram 152 includes anactuator 158 for driving a pinch plunger 160.

Operation of the embodiment of FIGURE 8 is substantially similar theembodiment of FIGURE 4. However, when the chamber 49 is pressurizedthrough the intake 78, the actuators 154 and 158 are also pressurized toex,- tend the opposed pinch plungers 156 and 160 respectively, wherebyto form the initial collapse or pinch 162 in the duct 48. After thepinch 162 is so formed, it provides a valve to prevent back flow and theremainder of the duct 48 can be collapsed to move the concrete or othercontained pumpage. Additional strength may be built into the duct 48 atthe locationof the pinch 162, if desired.

The probe rod 60 senses the conclusion of the pump cycle to relieve thepressure in the chamber 49 as described above. Thereupon, the pinchplungers 156 and 160 are also released permitting pumpage to be forcedinto the duct 48 during the next cycle.

The embodiment of FIGURE 8, as well as other embodiments hereof can bevariously incorporated in fluid control systems. For example, it may bedesirable to provide many individual pumps along an extended flow pathas shown in FIGURE 9. In that structure, a pair of pilot pumps control aseries of interconnected pumps to drive pumpage along a considerableflow path. Of course, the displacement between the individual pumps willdepend on the nature of the pumpage and the basic design considerationsof the system; however, for purposes of illustration only, the pumps inFIGURE 9 are shown contiguous.

The individual pump structures of FIGURE 9 may be similar to those asdescribed above and are designated P1, P2, P3, P4, P5, P6 and P7 inaccordance with their position in the interconnected series. The pumpsP1 and P2 are pilot pumps to which all the other pumps are slaveoperated. This is, all the odd numbered pumps operate in phase with thepump P1, while the even numbered pumps are slaved to the pump P2.Specifically, the pump P1 includes a probe structure extending from acontrol valve 172 which is adapted to be connected to a source of airunder pressure and provides an outlet through a line channel 174 to anactuator 176 that is connected to one end of a spool valve 178. In asimilar arrangement a probe structure 180 controls a valve 182 whichregulates air flow through a line-indicated channel 184 to an actuator186 that is connected to the spool valve 17 8 in opposition to theactuator 176. Various forms of well-known actuators may 'be employed asthe actuators 176 and 186 which exert a force in accordance with appliedpressure. One specific form of such actuator may be simply a pistonoperating in an orificed cylinder.

In the operation of the system of FIGURE 9, the series of pumps isconnected to a source of pumpage through a duct 190. An initial primingor charging may be necessary to load the first pump P1 in the series;however, some static head sulfcient to move the pumpage through the duct190 into the first pump P1 is assumed. Upon the pump P1 becoming filledwith pumpage, the probe structure 170 opens the valve 172 therebydeveloping increased force by the actuator 176 urging the spool valve178 to the left. At this time, the pump P2 is substantially empty sothat the valve 182 is essentially closed with the result that theactuator 186 exerts little force urging the spool valve 178 to theright.

The differential in forces applied to the spool valve 178 by theactuators 176 and 186 causes the spool valve to move to the leftconnecting the ducts 190 to a pressure duct 192, through the spool valvechamber 194. With the spool valve 178 in the left position, the ducts196' are connected to the discharge line 198 through the spool valvechamber 194.

Upon pressurization of the ducts 190, all the odd-numbered pumps P1, P3,and so on are pressurized to move pumpage into the next followingeven-numbered pumps. This movement continues until the probe structure170 senses that the pump P1 is substantially purged and the probestructure 180 senses the pump P2 is substantially full. Thereupon, theactuators 176 and 186 develop sufficient force differential to overcomethe static inertia of the system and displace the spool valve 176- tothe right, in the position shown. Thereupon, the pressure duct 192 isconnected to the ducts 196 to pressurize all the evennumbered pumps,while the odd-numbered pumps are relieved. In this manner, the system ispneumatically controllled to move pumpage, as over very great distances.Of course, it is to be appreciated that the actual control in varioussystems hereof may readily be electrical, hydraulic, pneumatic,mechanical or other. The basic principle being simply thesynchronization of the pressurization and relief of the pump apparatusin coordination with the flow of the pumpage.

In some applications of the system hereof it may be desirable to gangseveral individual pumps for seqeun-tial operation so as to assure auniform and constant flow of pumpage. One example of such a structure isshown in FIGURE 7, including two pumps 202 and 204 substantially asdisclosed in FIGURE 4. The operation of these pumps in alternatingsequence is accomplished by a spool valve structure 206 controlled byprobe structures 208 and 210 acting through an electrical system 212.

In the stage of operation in which the structure of FIG- URE 7 isdepicted, the pump 202 is purged and the pump 204 is full; the controlsystem has not altered the cycle to start purging the pump 204. Thisreversal occurs when an alternating electrical timer 214 provides acontrol voltage to a switch 216 to energize a solenoid 218, which shiftsthe position of a spool valve 220, from left to right through a pivotarm 222.

The electrical timer 214 may comprise any of the wide variety ofelectronic or electromechanical timers and serves to sequence theoperation of the system by alternately providing power to the switches216 and 218. A change in the state of the timer, however, does notreverse the cycle of the system unless the switches 216 and 218 are setby the probes 208 and 210 to indicate the proper state of the pumps fora reversal. This state is shown in FIGURE 7, as the pump 202 is purged.Therefore, when the spool valve 220 moves to the right, the air passage224 of the pump is connected through the spool valve chamber 226 to apressure line 228. Simultaneously, the air passage 230 of the pump 202is similarly connected to a relief passage 232. As a result, the pump204 moves pumpage through a duct 240 and past a flipper valve 242 into acommon channel 244. The valve 242 avoids possible back flow of thepumpage into the pump 202.

When the pump 204 is purged, the probe 210 closes the switch 218. Thisaction will then energize a solenoid 246, providing the electrical timer214 is energizing the switch 218. That is, the timer 214 affords a delaycontrol to regulate the pace of operation so as to assure adequate timefor each of the pumps to function.

Upon energization of the solenoid 246, the spool valve 220 is returnedto the position in which it is shown thereby pressurizing the pump 202from the line 228 to force pumpage out of the duct 250, and relievingthe pump 204 through a relief passage 252. Thus, the cycle recurs.

In the various exemplary embodiments as described herein certainfeatures are manifest. Specifically, it can be appreciated that thesystem is effective to control any of a wide variety of substance orpumpage, either by pumping the substance or by controlling the flowthereof as a valve action. Of course the latter structure may bepressure regulated to accomplish a nicety of control. Furthermore thesimplicity of the system is an indication of its durability, ease of useand economy of manufacture. Of course, various other features andstructural embodiments have been considered above and others will bereadily apparent to one skilled in the art; however, the scope hereof isnot to be accordingly limited but shall be interpreted in accordancewith the claims set forth below.

What is claimed is: 1. A pump for forcefully displacing pumpage, betweenan intake and an outlet during cyclic loading and exhausting operations,comprising:

a housing means defining a closed chamber; a flexible duct memberpositioned in said chamber whereby to receive pumpage from said intake;

cyclic-operating means for initially collapsing one portion of said ductwithin said chamber, contiguous to said intake where-by to initiate anexhaust flow from said duct member; and

cylic-operating means for varying the fluid pressure within said housingwhereby to provide a fluid pressure to alternately collapse and releasethe major other portion of said flexible duct whereby to force saidpumpage out of said outlet.

2. A system according to claim 1 wherein said means for initiallycollapsing one portion of said duct comprises:

:a vertical mounting stlucture for said flexible duct whereby to developa static head of said pumpage along said duct, which head is reducedcontiguous to said intake.

3. A system according to claim 1 wherein said means 'for initiallycollapsing one portion of said duct comprlses:

an actuator means to engagingly collapse said one portion of saidflexible duct.

4. A system according to claim 1 wherein said means for varying thepressure in said housing includes probe means to sense the state ofcollapse of said flexible .tube.

5. A system according to claim 4 wherein said flexible duct comprises 'acylindrical member having one end connected to said input and the otherend connected to said 'output, and further including a quantity ofincompressible fluid contained between said housing and said flexibleduct member.

6. A system comprising a plurality of structures as defined in claim 1,and including control means for said means for varying the pressurethereof, said control means :for alternately sequencing the operation ofsaid means for varying the pressure.

7. A system according to claim 6 wherein said control means comprises apneumatic structure for alternately supplying air under pressure to saidstructures.

8. A system according to claim 1 wherein said flexible duct comprises acylindrical member having one end raflixed to said input and one endaflixed to said outlet, and wherein said means for varying the pressureincludes means for sensing the state of collapse of said duct and meanscontrolled thereby to supply air under pressure to said housing means.

9. A system according to claim 8 further including: a hopper connectedto said intake and adapted to receive said pumpage; and blow out shieldmeans fixed between said hopper and said intake to restrict the flowtherebetween.

10. A system comprising a plurality of structures as defined in claim 9,and including control means for said means for varying the pressurethereof, said control means for alternately sequencing the operation ofsaid means for varying the pressure.

References Cited- UNITED STATES PATENTS 2,412,397 12/1941 Harper 1031482,478,568 8/1949 Coe 103-44 2,626,569 1/1953 Knudsen 103152 X 2,760,4368/1956 Von Seggern 103-44 3,007,416 11/1961 Chilcls 103-148 X 3,048,1218/1962 Sheesley 103152 3,250,226 5/1966 Voelker 103152 ROBERT M. WALKER,Primary Examiner.

1. A PUMP FOR FORCEFULLY DISPLACING PUMPAGE, BETWEEN AN INTAKE AND ANOUTLET DURING CYCLIC LOADING AND EXHAUSTING OPERATIONS, COMPRISING: AHOUSING MEANS DEFINING A CLOSED CHAMBER; A FLEXIBLE DUCT MEMBERPOSITIONED IN SAID CHAMBER WHEREBY TO RECEIVE PUMPAGE FROM SAID INTAKE;CYCLIC-OPERATING MEANS FOR INITIALLY COLLAPSING ONE PORTION OF SAID DUCTWITHIN SAID CHAMBER, CONTIGUOUS TO SAID INTAKE WHEREBY TO INITIATE ANEXHAUST FLOW FROM SAID DUCT MEMBER; AND CYLIC-OPERATING MEANS FORVARYING THE FLUID PRESSURE WITHIN SAID HOUSING WHEREBY TO PROVIDE AFLUID PRESSURE TO ALTERNATELY COLLAPSE AND RELEASE THE MAJOR OTHERPORTION OF SAID FLEXIBLE DUCT WHEREBY TO FORCE SAID PUMPAGE OUT OF SAIDOUTLET.